High pressure environment pressure actuation system

ABSTRACT

An actuation system for a downhole tool includes a first pressure compensated chamber receptive of a first chemical therein. A second pressure compensated chamber receptive of a second chemical therein. A pressure actuated trigger having a first position wherein the first and second chambers are segregated from each other and a second position wherein the first and second chemicals are no longer segregated from one another.

BACKGROUND

In the drilling and completion industry, many types of downhole tools are needed for various functions. An appreciable number of those must be run in the hole (RIH) in an unset position and then actuated to a set position. Due to a myriad number of distinct environmental and borehole design conditions, there are different types of actuating constructions. Some are mechanical, some are electrical, some are hydrostatic, etc.

Hydrostatic actuation systems work well for their intended purposes in boreholes for many years but with the increasing depths and consequent increasing hydrostatic pressures encountered, such systems have difficulty performing as reliably as an operator would prefer. And when a tool fails to operate as intended, the costs involved are usually quite high especially in such very deep borehole due to the time and cost of tripping the tool back to surface for repair or replacement before operations can resume.

Efficiency is paramount in all borehole operations and accordingly, the art well receives new concepts for ensuring reliable tool actuation.

BRIEF DESCRIPTION

An actuation system for a downhole tool includes a first pressure compensated chamber receptive of a first chemical therein; a second pressure compensated chamber receptive of a second chemical therein; a pressure actuated trigger having a first position wherein the first and second chambers are segregated from each other and a second position wherein the first and second chemicals are no longer segregated from one another.

An actuation system includes a body; an outer housing connected to the body and creating an annular space between the body and the outer housing; a trigger body disposed within the space and exposed to ambient pressure at one end thereof; an isolator spaced from the trigger body within the annular space to create a pressure compensated chamber; a setting piston spaced from the isolator within the annular space to create a pressure compensated chamber; a prong extending from the setting piston through the isolator to the trigger body, the prong being in sealed relationship with each in a first position.

An actuation system includes a chemical based force generator; a pressure based trigger for the chemical based generator in operable communication with the chemical based generator.

BRIEF DESCRIPTION OF THE DRAWINGS

The following descriptions should not be considered limiting in any way. With reference to the accompanying drawings, like elements are numbered alike:

FIG. 1 is a schematic quarter sectional view of an actuator as disclosed herein in a run in position;

FIG. 2 is an enlarged view of a portion of FIG. 1 delineated by a box in FIG. 1, still in the run in position;

FIG. 3 is the view of FIG. 2 in a position where hydrostatic pressure has risen due to depth of the system,

FIG. 4 is a view similar to FIGS. 2 and 3 but representing somewhat more of FIG. 1 and in a triggered position:

FIG. 5 is the view of FIG. 4 in a first actuation position

FIG. 6 is the view of FIG. 4 in a final actuation position.

DETAILED DESCRIPTION

A detailed description of one or more embodiments of the disclosed apparatus and method are presented herein by way of exemplification and not limitation with reference to the Figures.

Referring to FIGS. 1 and 2, an actuation system 10 is illustrated that may be connected to any tool (not shown) requiring a load to be actuated through for example the setting sleeve 12 as illustrated. Such tools include packers, other seals, sliding sleeves, etc.

The actuation system 10 as illustrated includes a body 14. Body 14 includes two features that provide other than sliding contact with other components of the system described below. These are a one direction configuration 16 and a dog profile 22. Referring to the one direction configuration, the illustration show a ratchet 18 on a surface of the body 14 and a pawl type device 20 such as a body lock ring that is interactive with both the body and the ratchet as further discussed below. Movement of the device 20 is limited to one direction relative to the ratchet 18. Dog profile 22 is interactive with a dog 24 to anchor components in place until a particular time related to action of the system.

Attached to the body 14 is an outer housing 26 that provides between itself and the body 14 an annular space in which other components of the system are disposed. It is to be appreciated prior to moving on to the other components that there are two openings 30 and 32 in the outer housing 26 each of which remains open to annulus pressure during actual use of the tool in a borehole environment. This is important with respect to the control of collapse forces, one of the advantages gained through use of this disclosure. More specifically, the openings allow annulus pressure to reach both ends of the operative components of the system described for a balanced pressure condition and reduction in the system of lower pressure volumes, which otherwise would have an impact on collapse ratings for the system.

Actuation system 10 includes generally a trigger and a force generator. The trigger in this embodiment is related specifically to annulus pressure whether that be hydrostatic, and therefore relatively automatic upon reaching a certain depth during running, or selective through the use of pressuring up from surface or other location or even a combination of hydrostatic and active pressurization. The generator is chemically based and produces a gas evolution reaction, an exothermic reaction, an energetic reaction or any other reaction that causes the volume of chambers (discussed below), within which a first and second chemical are housed, to increase due to the reaction. Chemicals may be in a liquid phase in some cases (or even solid or gaseous form providing they are reactable)and may be for example hydrogen peroxide (maintained prior to triggering in one chamber and a catalyst such as iron chloride or potassium iodide maintained segregately prior to triggering in another chamber, for example.

Beginning arbitrarily at the downhole end (right in the figure) of the system 10, components include a trigger body 36 having seals 38. In the illustration, the trigger body 36 is annularly shaped and hence each seal 38 is a doughnut concentric with the body 14 but it is to be appreciated that the components could be arranged in one or more annularly discontinuous portions with dimensions to fit within the annular space between the body 14 and outer housing 26. The discontinuous portions may represent cylinders or other elongated geometric shapes subject only to pressure sealability to surrounding structure.

Trigger body 36 further includes a defeatable member 40 such as a burst disk disposed to close a passage 44 in trigger body 36. The passage 44 leads to a chamber 46 still within trigger body 36. Chamber 46 is maintained at a pressure less than hydrostatic pressure and is in some embodiments atmospheric pressure. While one of skill in the art will recognize a lower pressure chamber as a challenge to collapse rating of a tool, it is pointed out that the chamber 46 as illustrated is a small volume with significant structure surrounding it. Accordingly, it represents a very small impact on collapse rating. Further, a retainer is positioned adjacent the chamber 46 whose function and location will be addressed later during discussion of operation.

Within the chamber 46 is an isolation plug 48. The plug 48 is in sealed sliding relationship with the chamber 46 through seals 50. Connected to plug 48 is prong 54 having at least two diameters. One is at piston end 56 and another is at a turned down portion 58. The piston end 56 has the same diameter as isolation plug 48 to ensure a balanced pressure operation. Piston end 56 is operably slidingly sealed to both an isolator 60 at a bore 62 through the isolator 60 at seals 64 and to a setting piston 66 through seals 68 at bore 70 that represents another lower pressure chamber 72 (atmospheric pressure in some embodiments) that will be at a same pressure as chamber 46 during manufacture of the system. Chamber 72 is also small in volume and surrounded by significant structure such that its impact on collapse rating is negligible.

It is to be understood that each of trigger body 36, isolator 60 and setting piston 66 are slidably disposed between outer housing 26 and body 14, and each are sealed to ⁻these structures by seals 74, 76, 78, 80, 82, 84. This allows for the components to move in reaction to the increasing annulus pressure that accompanies depth of the system during running. Such movement is important to the embodiment because between the components, 36, 60 and 66 are defined two pressure compensated chambers 86 and 88. These chambers 86 and 88 represent sizable volumes that but for the configuration of the embodiments disclosed herein could impact a collapse rating of the system. As it is configured however, due to the ability of components 36, 60 and 66 to slide while being pressure sealed the chambers 86 and 88 change volume compressing contents therein to match the pressure external thereto as it increases. This is illustrated in a comparison of FIGS. 2 and 3. It can be readily appreciated that chambers 86 and 88 are smaller as depicted in FIG. 3 than they are depicted in FIG. 2. One will also appreciate that the one direction configuration 16 has moved to the left in the figure. This has occurred due to annulus pressure increasing commensurate with tool depth, that pressure being communicated to the body trigger through the opening 30. It should be noted that at this point in operation of the system 10, setting sleeve 68 has not moved even in relation to the increasing annulus pressure to which it is exposed through opening 32 because of the restrictive effect of a release member 90 visible in FIG. 1. Accordingly, the volume of chambers 86 and 88 as well as the resultant pressures therein are responsive to the movement of trigger body 36 alone. Pressures within chambers 86 and 88 consequently will equal that of annulus pressure. This ensures that none of seals 74, 76, 78, 80, 82, 84 are required to maintain a pressure differential across the seal. The ratchet prevents the trigger body 36 moving back in the downhole direction as later in operation of the system, pressure builds in the chambers 86 and 88.

Turning to operation of the system 10, reference is made to FIGS. 4, 5 and 6. FIG. 4 depicts the system 10 in a position following sufficient pressure rise through opening 30 to open defeatable member 40. Annulus pressure, whether hydrostatic or as a pressure up condition from surface acts on plug 48 to move it leftwardly in the drawing moving prong 54 further into lower pressure chamber 72. It will be appreciated by a comparison of FIG. 3 and FIG. 4 that the result of the movement just described is piston end 56 moving out of engagement with isolator 60 thereby allowing fluid whether liquid gas or even a particulate solid capable of flowing fluidly) communication between chambers 86 and 88. At this point, chemicals provided in chambers 86 and 88, that had been segregated until this point are no longer segregated meaning that they can interact. One or more of the reactions described above will begin and since trigger body 36 cannot move to the right in the figures due to the configuration 16, all force created by the chemical reaction will be a driving force for components to the left of trigger body 36 in the figure.

Moving to FIG. 5, the first action that will occur, once the actuation force of the chemical reaction grows to a sufficient threshold, is the release of release member 90. Since release member 90 is an impediment to the setting piston moving, its release will allow the setting piston 66 to move leftwardly in the figure. This positions a window 92 in setting piston 66 radially outwardly of the dog 24 meaning that the dog 24 is no longer retained in the profile 22. At this point another feature of the dog 24 is noted. That is an inclined surface 94 which interacts with an inclined surface 96 in setting sleeve 12. The two surfaces work together to urge the dog 24 out of engagement with the profile 22 thereby allowing the setting piston to move further leftwardly in the figure and now to transfer the energy thereof to the setting sleeve 12. Setting sleeve 12 will transfer the load it receives to whatever tool is attached thereto in order to set the same.

Referring to FIG. 6, the system 10 is depicted in the final position where it can be seen that the setting piston 66 and setting sleeve 12 are moved significantly to the left in the figure. It is also to be noted that the prong 54 is no longer engaged in bore 70 and that isolator 60 has moved leftwardly as well. Since the movement of isolator 60 too far in that direction can potentially be detrimental to system function, a stop 98 is provided that interacts with isolator 60 at shoulder 100 to prevent excessive movement of the isolator 60. Also to be noted is that because of the potential freedom prong 54 has in connection with FIGS. 4, 5 and 6, a retainer 102 is placed at trigger body 36 to prevent isolation plug 48 leaving chamber 46, which would result in a leak path for the reaction product of the chemicals in chambers 86 and 88 through the trigger body 36 to the annulus, which would reduce functionality of the system 10.

The use of the terms “a” and “an” and “the” and similar referents in the context of describing the invention (especially in the context of the following claims) are to be construed to cover both the singular and the plural, unless otherwise indicated herein or clearly contradicted by context. Further, it should further be noted that the terms “first,” “second,” and the like herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another. The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., it includes the degree of error associated with measurement of the particular quantity).

The teachings of the present disclosure may be used in a variety of well operations. These operations may involve using one or more treatment agents to treat a formation, the fluids resident in a formation, a wellbore, and/or equipment in the wellbore, such as production tubing. The treatment agents may be in the form of liquids, gases, solids, semi-solids, and mixtures thereof. Illustrative treatment agents include, but are not limited to, fracturing fluids, acids, steam, water, brine, anti-corrosion agents, cement, permeability modifiers, drilling muds, emulsifiers, demulsifiers, tracers, flow improvers etc. Illustrative well operations include, but are not limited to, hydraulic fracturing, stimulation, tracer injection, cleaning, acidizing, steam injection, water flooding, cementing, etc.

While the invention has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the claims. Also, in the drawings and the description, there have been disclosed exemplary embodiments of the invention and, although specific terms may have been employed, they are unless otherwise stated used in a generic and descriptive sense only and not for purposes of limitation, the scope of the invention therefore not being so limited. 

What is claimed is:
 1. An actuation system for a downhole tool comprising: a first pressure compensated chamber receptive of a first chemical therein; a second pressure compensated chamber receptive of a second chemical therein; a pressure actuated trigger having a first position wherein the first and second chambers are segregated from each other and a second position wherein the first and second chemicals are no longer segregated from one another.
 2. An actuation system for a downhole tool as claimed in claim 1 wherein the first and second pressure compensated chambers are volume changeable in response to ambient pressure, thereby changing pressure within the pressure compensated chambers.
 3. An actuation system for a downhole tool as claimed in claim 1 wherein the first and second pressure compensated chambers are at atmospheric pressure prior to running of the system into a borehole.
 4. An actuation system for a downhole tool as claimed in claim 1 wherein the first and second pressure compensated chambers are segregated by an isolator and a prong in sealed connection therewith.
 5. An actuation system for a downhole tool as claimed in claim 4 further including a trigger body in operable communication with the prong.
 6. An actuation system for a downhole tool as claimed in claim 5 further including a setting piston in operable communication with the prong.
 7. An actuation system for a downhole tool as claimed in claim 6 wherein all claimed components are disposed within an annular space between a body and an outer housing of the system.
 8. An actuation system comprising: a body; an outer housing connected to the body and creating an annular space between the body and the outer housing; a trigger body disposed within the space and exposed to ambient pressure at one end thereof; an isolator spaced from the trigger body within the annular space to create a pressure compensated chamber; a setting piston spaced from the isolator within the annular space to create a pressure compensated chamber; a prong extending from the setting piston through the isolator to the trigger body, the prong being in sealed relationship with each in a first position.
 9. An actuation system as claimed in claim 8 wherein the trigger body further includes a defeatable member.
 10. An actuation system as claimed in claim 9 wherein the defeatable member is pressure defeatable.
 11. An actuation system as claimed in claim 8 wherein the trigger body, the isolator and the setting piston are movable within the annular space to change a volume of the pressure compensated chambers based upon ambient pressure on the system.
 12. An actuation system comprising: a chemical based force generator; a pressure based trigger for the chemical based generator in operable communication with the chemical based generator.
 13. An actuation system as claimed in claim 12 wherein the chemical based generator includes a plurality of pressure compensated chambers that are segregated until the pressure based trigger is triggered.
 14. An actuation system as claimed in claim 13 wherein the pressure based trigger upon being triggered communicates the plurality of chambers allowing a chemical reaction that results in the generation of an actuation force.
 15. An actuation system as claimed in claim 12 wherein the chemical based generator includes hydrogen peroxide and a catalyst such as iron chloride or potassium iodide. 